Fish Fat Meter used to study & evaluate an acoustic mobile tracking device in adult Pacific Lamprey

Title	Adult Pacific Lamprey Migration Behavior And Escapement In The Bonneville Reservoir And Lower Columbia River Monitored Using The Juvenile Salmonid Acoustic Telemetry System (Jsats), 2011
Written by	C.J. Noyes, C.C. Caudill, T.S. Clabough, D.C. Joosten, E.L. Johnson, M.L. Keefer, G.P. Naughton
From	University of Idaho, USA
Published	May 2012
Fish Species	Pacific Lampreys (Entosphenus tridentatus))

What the research is about

The article discusses a study conducted in 2011 to evaluate the migration behavior and fate of adult Pacific lamprey in the Bonneville Reservoir and the lower Columbia River using the Juvenile Salmonid Acoustic Telemetry System (JSATS). The researchers used JSATS transmitters and half-duplex (HD) PIT tags to monitor the upstream passage and migration of tagged adult Pacific lamprey. The study aimed to calculate lamprey travel times, estimate escapement past the monitored sites, and evaluate JSATS detection efficiency.

The Fish Fat Meter, a device used to measure muscle lipid content, played a role in characterizing the tagged lamprey population. The researchers measured the length, girth, weight, and percent lipid content (using the Fish Fat Meter) of the lamprey during the tagging process. This information provided insights into the physiological condition of the tagged individuals and allowed for comparisons with other tagged groups.

Research conclusion

A key conclusion highlighted in this study showed an improved ability to track Lamprey migration using JSATS method and identified the upper Bonneville Reservoir as an area requiring further monitoring to resolve the final fates of many tagged individual Lamprey’s.

Based on the results and discussion in this article, below are some key findings:

1. The JSATS acoustic telemetry system allowed the researchers to effectively monitor the migration behavior and determine the final fates of adult Pacific lamprey in deep water habitats like Bonneville Reservoir and tailraces, which was a limitation of previous radio and PIT telemetry studies.
2. The majority (84%) of the lamprey that entered or were released into Bonneville Reservoir were detected passing through most of the reservoir and reached the Lyle receiver gate about 16 km from The Dalles Dam. This suggests that unaccounted losses during summer/fall migration are not strongly occurring in the lower two-thirds of Bonneville Reservoir.
3. The final fates and distributions of many tagged lamprey remained unresolved, with several potential explanations discussed, such as overwintering in The Dalles Dam tailrace, moving into tributaries for spawning in spring, experiencing pre-spawn mortality, or being subject to predation.
4. Lampreys exhibited relatively rapid migration rates through reservoir reaches compared to dam passage, consistent with previous studies. Migration rates did not show significant correlations with factors like release date, body size, or temperature.
5. There was no evidence that the JSATS transmitter had additional tagging effects on lamprey migration compared to the HD-PIT tag, though sample sizes were modest for this comparison.